Changing Behavior

The only time I had to change my behavior alot that I can remember was two summers ago. My older sister tripped me and pushed me down the steps and I got super mad. My little sister saw the whole thing because she was brushing her teeth nearby. So I went down a flight of stairs but managed to hold onto the railing before falling to the ground. So yeah I screamed and started yelling at my sister. My mom and dad didn't believe me when I told them. Neither did they believe my little sister. So she pretty much my older sister got away with what she did. I had to change my behavior or attitude pretty quickly cause my little sisters birthday was a few hours after.